SPOILERS AHEAD!! (You have been warned)
Aribeth pops up yet again as a recruitable party member in the third chapter of the Neverwinter Nights expansion Hordes of the Underdark. She's now a paladin/blackguard (a neat combo that actually makes sense in light of the events in Neverwinter Nights' OC) and is one of the more powerful henchmen available. There is also a romance script if your main character is male. It involves her revelation that she never really loved Fenthick. This, to anybody who has seen her Greek tragedy-esc fall in the original campaign, should stink of a quickly contrived way to allow your good-aligned character to get into her pants in the relatively short time of Hordes, and not feel bad about it. Other then that, it was a rather good romance script, though not on level with those in Baldur's Gate II.
A few odd facts: Aribeth's race was changed for Hordes of Underdark. She is now referred to as a half-elf rather then a full elf, as she was in Neverwinter Nights. Since her race is referred to quite a few times in each game the change is just weird. Perhaps the folks at Bioware decided that half-elves were just more angsty-cool and hoped nobody would notice?
Aribeth has often been shown, both in numerous pin-up type illustrations, and in the between scene movies of the original campaign, to be wielding a pair of swords. In the games themselves she's wielded a longsword, longsword and shield, or bastard sword but never a pair of swords. She doesn't have the feats for it (i.e., ambidexterity and two-weapon fighting).